1) add a global variable spawnTime and set it to 1.2) replace the "1.0" in each "every 1.0 seconds "so that it reads "every spawnTime seconds".3) on power-up collected change the value of spawnTime from 1 to 2.

Yep. As mekonbekon has said, use a variable to control things that you want to, vary, at runtime.

Using variables is an easy yet powerful way to change anything in your code on the fly... I even use them in the design process when I'm experimenting with things, so that I don't have to change a value in 10 different events... I can just change a global variable value and it does everything else for me!